Exoplanet discoveries continue to grow as NASA’s official count hits 6,000

NASA has revealed that there are 6,000 known planets outside the solar system. This report marks a further step in the search for exoplanets - planets that lie beyond the Sun's orbit.

NASA's Exoplanet Archive, a repository that chronicles findings from both space missions and observatories on the ground, published the roster this week. The archive is under the supervision of the California Institute of Technology, located in Pasadena, and it is the official source of the planet confirmation list.

What the 6,000 milestone means 

Scientists first discovered exoplanets during the 1990s which led to fast expansion of this scientific discipline. The 6,000 mark reflects three decades of discoveries made by missions such as Kepler, TESS (Transiting Exoplanet Survey Satellite), and other international telescopes.

NASA officials explained that the number represents only confirmed planets. The list contains thousands of "candidates" which will get added later when scientists finish their data analysis. Exoplanets exist in various dimensions and follow different orbital trajectories and possess diverse chemical compositions.

The planets show a range of sizes from Earth-like dimensions to massive bodies that match Jupiter in scale. Scientists examine these distinctions to comprehend the development of planetary systems and their ongoing changes.

​How exoplanets are discovered

Most exoplanets have been detected using the transit method. This involves observing a star for small dips in brightness caused when a planet passes in front of it. Another approach, the radial velocity method, measures tiny shifts in a star’s motion caused by the pull of an orbiting planet.

Space missions like Kepler pioneered the transit method, producing thousands of discoveries. Today, the TESS spacecraft continues that work by scanning nearly the entire sky for new candidates. Ground-based observatories complement these efforts, often confirming or refining measurements from space missions.

Why exoplanet research matters

Researching planets that are not part of our solar system helps scientists to compare them with Earth, and the other nearby planets. 

Although the investigation with the main goal of discovering life is only one part of the work, most of the scientists' work is dedicated to clarifying the picture of the planetary systems' development. 

The confirmed planets are 6,000 in number and they consist of gas giants, rocky worlds, and planets orbiting starting from very close to their stars and going far away. 

The variety has changed the ideas of what planetary systems can be like. In fact, a big number of exoplanets have been discovered to be orbiting very close to their stars, making them quite different from our solar system.

New technologies are going to be used by NASA and its collaborators to keep looking for extraterrestrial and studying them. At this time, one of the main contributors to the field is the James Webb Space Telescope with its very thorough observations of exoplanet atmospheres.

Satellites that will be launched later are expected to deepen these attempts and maybe even find planets that have more similarities with our Earth. As the number of confirmed exoplanet discoveries increases, so does the size of the exoplanet archive, and the knowledge of the existence of planets similar to ours becomes also bigger.